It’s only the fourth day of JR311 today and even this early in the cruise I’m ecstatic! After a long mobilisation, which is inevitable when there is so much equipment to prepare for a research cruise out into the wintery Southern Ocean, we’ve just completed the second of our long Seasoar transects through the subantarctic and polar fronts and a dynamically significant filament in the region to the north. Despite some challenging weather, in particular last night when cabin contents were strewn across the floor as the ship was rolling 20° in 50 knot winds and 5m waves, the results so far are all we had hoped for. Sharp fronts are clearly evident in the towed CTD sections both at the filament and within the narrow region encompassing the subantarctic and polar fronts. The latter region in particular was spectacular; the eastward flowing Antarctic Circumpolar Current reached almost 2 m s-1 and we can clearly see oxygen-rich Antarctic Intermediate Water being subducted down into the ocean interior. As I write this we’ve started the third section through the filament, on the northern edge of which we plan to start the tracer release experiment tomorrow.
The scientific team has done a great job so far in keeping on top of both the equipment and the data analysis, particularly given the conditions being thrown at us by the Southern Ocean. Many members of the team are at sea for the first time, which makes their resilience all the more impressive given the environment. There are still some who are finding their sea legs but better weather is forecast tomorrow for the next few days so hopefully everyone will be well seasoned by the time a decent storm forecast for later next week arrives. For the rest of today we’re preparing the sensors for the instrumented drifters to be released during the tracer release experiment during which we are planning to detect the circulations associated with submesoscales. The Seasoar results suggest that the northern edge of the filament is highly conducive to their formation so fingers crossed for tomorrow!